function [a,b]=factor1(c)
 [theta,phi,r]=cart2sph(c(1),c(2),c(3));
 phi2=pi/2-phi;
 [x1,y1,z1]=sph2cart(theta,-phi2,sqrt(r));
 a=[x1 y1 z1];
 [x2,y2,z2]=sph2cart(pi/2+theta,0,sqrt(r));
 b=[x2 y2 z2];
endfunction
